1. Field of the Invention
This invention is related to a railway diesel engine lubricant having improved properties of inhibition of oxidative and corrosive effect. More particularly, this invention relates to anti-oxidation and anti-corrosion additives for railway diesel lubricants used in railway diesel engines.
Over the past ten years the price of diesel fuel has increased dramatically. As an example, the price of marine diesel fuel has increased from $11 a metric ton to currently about $200 a metric ton. Additionally, a similar increase in fuel cost has been experienced by the railroad industry. These increases have resulted in the cost of fuel being the largest expense for the owners of any diesel fleet of vehicles. To try to obtain some relief from this large expense the railroads have embarked on a program of mixing poorer grade fuels (such as marine residual) with the regular D-2 diesel fuel. While they do realize a savings from this mixed fuel operation, other engine performance problems arise, such as increased corrosion and poorer oxidative stability. The proportions of the problems can be observed when one sees General Electric spending $20 million dollars to build new test facilities to evaluate the parameters involved and General Motors (EMD) exerting a similar type of effort to also study the problem.
The present invention deals with the scenario where diesel fuel (D-2) is extended with diesel residual fuel, as proposed by the railway industry. As a result, railway diesel oil (RDO) will be subjected to more severe conditions during operation. We have simulated the scenario wherein RDO is contaminated with a given amount of marine diesel residual fuel. We believe this to be a realistic test since during normal engine operation D-2 gets into the diesel crankcase. We used the Union Pacific Oxidation Test (UPOT) to evaluate the effectiveness of the experimental additives in reducing corrosion and oxidative thickening of the RDO.
2. Disclosure Statement
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U.S. Pat. No. 4,290,778 discloses the use of the reaction product of a hydrocarbyl alkoxyalkylene diamine and maleic anhydride as a corrosion inhibitor and carburetor detergent additive in motor fuels.
U.S. Pat. No. 4,207,079 discloses the use of the reaction product of maleic anhydride and certain alkyl-alkylene diamines as a corrosion inhibitor and a carburetor detergent additive in motor fuels.
U.S. Pat. No. 4,144,034 discloses the use of the reaction product of a polyether amine and maleic anhydride as a carburetor detergent and corrosion inhibitor in motor fuels.
U.S. Pat. No. 3,773,479 discloses the use of the reaction product of maleic anhydride and alkyl or alkylene amines as a carburetor detergent, corrosion inhibitor, and anti-icing additive in motor fuels.